package DataStructureAndAlgorithm.AcWing_每日一题.枚举;

import java.util.Scanner;


//链接：https://www.acwing.com/problem/content/description/3794/
class AcWing_3791{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String str = in.next();
        String res = str.valueOf(str.charAt(0));
        //分奇偶两种情况讨论即可
        if (n % 2 == 1){
            for (int i = 1; i < n; i++){
                if (i % 2 == 1){
                    res = str.valueOf(str.charAt(i)) + res;
                }else {
                    res = res + str.valueOf(str.charAt(i));
                }
            }
        }else {
            for (int i = 1; i < n; i++){
                if (i % 2 == 0){
                    res = str.valueOf(str.charAt(i)) + res;
                }else {
                    res = res + str.valueOf(str.charAt(i));
                }
            }
        }

        System.out.println(res);

        in.close();
    }
}
